Dennis Dimick: 'Living In The Human Age'

Farming in Quebec south of the St. Lawrence River at Quebec City. ( Dennis Dimick )

Dennis Dimick wants you to see what he sees. As a journalist and photographer working for the National Geographic for 35 years, Dimick has traveled the globe and witnessed the effects of the Anthropocene, which means The Human Age.

Dimick delivered the sixth Henry C. Gardiner Global Food Systems Lecture on Monday at Kansas State University. The lecture can be viewed here.

The term Anthropocene was coined about 20 years ago by scientists to describe the new era of geologic history where humans have become the dominant species on earth, and the impacts of our expanding activities can now be observed in the geology of the planet.

“Since about 1950 we have seen what is called the ‘Great Acceleration,’” Dimick says, “a tripling of human population, a dramatic rise in energy use primarily from coal, oil and natural gas for electricity, industrialization, and urbanization, and vast land use change for agriculture and urbanization. We have cut forests and plowed up grasslands to grow more food for this rising population, and to give us places to work and live.”

Modern society depends on fossil fuels to work, he says, and agriculture itself is deeply reliant on fossil fuels to grow crops, as oil is needed for tillage, harvest, transportation and chemicals, and natural gas is used to produce nitrogen crop fertilizer.

That sounds a lot like a description of climate change, but Dimick says the Anthropocene is much more than that. Essentially climate change is one symptom or result of the Anthropocene.

To help others see and understand what he has witnessed, Dimick has developed a fast-paced slide show called “Living in the Human Age,” which explains the challenges of living in the modern human era. 

Agriculture roots

Dimick is the son of fisheries biologists raised on a farm in Oregon’s Willamette Valley. Actively involved in 4-H and FFA as a boy, Dimick harbored early dreams of pursuing a career as a biologist or forest ranger.

As a young man, he witnessed the impact of human progress when his family’s farm was cut in half by an interstate highway. He also saw clear-cut logging of nearby forests, events that combined to sensitize him to the effects of the Anthropocene. Early photography experience and his personal connection to the effects of human progress led to a life and career spent combining these two dimensions.

Dimick earned a degree in agricul­ture from Oregon State University, and a degree in agricultural journalism from the University of Wisconsin- Madison. He spent 35 years at National Geographic, serving for over a decade as the magazine’s environment editor, and guided major projects on climate change, energy, freshwater, population and food security. He twice was involved in magazine stories on the High Plains Aquifer, a major source of groundwater in western Kansas and parts of seven other states. In 2014 he conceived and led a multiyear series titled, “The Future of Food,” on global food security.

The goal of his lectures, which he’s presented since 2010, is to create a larger framework than just climate change. While climate change is one result of the Human Age, he says there are other symp­toms such as “deforestation, declin­ing aquifers, species extinctions, air pollution from engines and industry, and accumulating hypoxic, or ‘dead zones’ in coastal waters from nutri­ent runoff from urban and agricul­tural landscapes. These are all results of expanding population, energy use, and land use changes.”

In our urgency to produce more food to satisfy a rapidly expanding human population, Dimick says we have converted natural plains and grasslands into vast fields of industrial-scale monoculture crop production.

“Nearly 70% of world freshwater is used for irrigation, (so) we are depleting aquifers,” Dimick explains. “We have cut forests all over the world to grow crops to feed people, to grow crops to feed animals that we eat, or even grow crops that we turn into fuel.”

He acknowledges there are great benefits to humanity in the crops and food produced, but the loss of biologically diverse forest and plains landscapes also comes at a price, such as loss of carbon storage in soil, and species extinctions.

“These impacts add up,” he says. “One effect is that we are altering atmospheric chemistry, as fossil fuel burning and land use change produce the heat-trapping gases carbon dioxide and methane, and global temperatures are rising. The warmest five years since modern weather records began have been the past five years.”

Humans also extract nitrogen from the atmosphere using natural gas in a process called Haber-Bosch to produce synthetic nitrogen fer­tilizer that has become the primary plant food for grain production.

“This easily-available nitrogen plant food has created a dramatic rise in food supplies, but we also disrupt the planet’s nitrogen cycle as surplus nutrient runoff from landscapes pollutes groundwater and coastal waters.”

In the Human Age, Dimick says, “We are deeply intertwined with coal, oil and gas, as these essential energy sources make possible the civilizations and economies in which we live. But what we now witness are changes in the behavior of several of earth’s major cycles, such as carbon, nitrogen and water.”

Using the Anthropocene, or Human Age framework as a way to contemplate these changes offers a broader context and helps us under­stand why earth’s climate is chang­ing, not just that it is.

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